We present a long range (~250 m) time-of flight (TOF) system with suppressed (nearly-free) mutual-interference. The system is based on a $1296\times960$ pixels vertical avalanche photodiodes (VAPD) CMOS image sensor (CIS). Real-time long-range 3D-imaging with 30 fps speed (450 fps for 2D imaging) is demonstrated. Designs and operation principles of the core circuits, i.e., a photon counting circuit and a global shutter driver, are fully described. The ranging method is based on a sub-range synthesis (SRS) where a range is set by the phase of exposure pulses with respect to that of the light source of the system. The depth resolution is configurable in that the minimum sub-range width limited by the light source pulse width of 10 ns or 1.5 m can be reduced to a 10 cm by introducing an indirect-TOF operation. Furthermore, by employing a random flight timing (RFT), mutual-interference in raw signal level is suppressed by 35 dB when 2 cameras are simultaneously operated. By simulation, the present system is estimated to be tolerant up to a case of 27 cameras operation.

中文翻译：

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基于百万像素垂直雪崩光电二极管 CMOS 图像传感器的几乎无干扰且深度分辨率可配置的飞行时间系统

我们提出了一种具有抑制（几乎无）相互干扰的远程（~250 m）飞行时间（TOF）系统。该系统是基于一个 $1296\times960$像素垂直雪崩光电二极管 (VAPD) CMOS 图像传感器 (CIS)。演示了速度为 30 fps（2D 成像为 450 fps）的实时远程 3D 成像。详细描述了核心电路的设计和工作原理，即光子计数电路和全局快门驱动器。测距方法基于子范围合成 (SRS)，其中范围由曝光脉冲相对于系统光源相位的相位设置。深度分辨率是可配置的，因为通过引入间接 TOF 操作，可以将受 10 ns 或 1.5 m 光源脉冲宽度限制的最小子范围宽度减少到 10 cm。此外，通过采用随机飞行定时 (RFT)，当同时操作 2 个相机时，原始信号电平的相互干扰被抑制了 35 dB。通过模拟，